UWB system

ABSTRACT

Disclosed is an ultra-wideband (UWB) system and, more particularly, a UWB system using UWB ranging factor definition. The UWB system using the UWB ranging factor definition includes a memory in which a UWB ranging factor definition program is embedded and a processor which executes the program, wherein the program predefines UWB ranging factors to define a scrambled timestamp sequence (STS) index, an encryption key, and a nonce.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2020-0135358, filed on Oct. 19, 2020, and KoreanPatent Application No. 10-2020-0160545, filed on Nov. 25, 2020, thedisclosure of which is incorporated herein by reference in its entirety.

BACKGROUND 1. Field of the Invention

The present invention relates to an ultra-wideband (UWB) system, andmore particularly, to a UWB system using a UWB ranging factordefinition.

2. Discussion of Related Art

Ultra-wideband (UWB) technology is a technology that calculates adistance between entities by multiplying a signal arrival time betweencommunication entities by the speed of light using a time-of-flight(ToF) technique of ultra-wideband (6 to 8 GHz with a bandwidth of over500 MHz).

According to the related art, digital-key (smartphone) UWB rangingfollows an operation sequence defined in the international standard suchas the Car Connectivity Consortium (CCC).

According to the related art, the corresponding standard associationsuggests that various ranging factors (e.g., a scrambled timestampsequence (STS) indexes, an encryption key, etc.) that need to beselected for UWB communication should be exchanged with smartphonesusing other communication means (near-field communication (NFC), BLE,etc.) through pre-handshaking. However, the smart key system accordingto the related art has restrictions on the use of such communicationmeans (NFC, BLE, etc,) and the pre-exchange of keys.

SUMMARY OF THE INVENTION

The present invention is proposed to solve the above problems and isdirected to providing a UWB system that defines a ranging factor andmaintaining the same level of security when applying a UWB rangingsequence defined by the international standard (Car ConnectivityConsortium (CCC)).

According to an aspect of the present invention, there is provided aultra-wideband (UWB) system using a UWB ranging factor definition, theUWB system including a memory 107 in which a UWB ranging factordefinition program is embedded and a processor 108 which executes theprogram, wherein the processor 108 predefines UWB ranging factors todefine a scrambled timestamp sequence STS index, an encryption key, anda nonce.

The processor 108 defines an STS index as plaintext that has to beencrypted to generate an STS.

The processor 108 defines STS encryption key, Data encryption key, andSTS Index encryption key as the encryption keys.

The processor 108 defines Salt, source (SRC) Address, and RandomCounteras the nonces.

The processor 108 defines an STS index, an encryption key, and a noncein consideration of characteristic information by using encryption keyvalues that are created based on a random value provided by a device ora seed value provided by a vehicle according to the same rule.

The processor 108 determines an STS index in consideration of acharacteristic of a 4-byte random value that is changed every ranging.

The processor 108 determines an encryption key in consideration of aunique 16-byte key characteristic for each set of a vehicle and a device(smart key).

The processor 108 determines a nonce in consideration of a unique keycharacteristic (a fixed value different for each smart key) of anindividual device (smart key).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a problem of time-slotted channel hopping (TSCH) inthe related art.

FIG. 2 shows an ultra-wideband (UWB) module application band accordingto an embodiment of the present invention.

FIG. 3 shows a UWB system according to an embodiment of the presentinvention.

FIG. 4 shows frequency-hopping according to an embodiment of the presentinvention.

FIG. 5 illustrates a UWB operation method according to an embodiment ofthe present invention.

FIG. 6 illustrates UWB modeling, UWB antenna specifications, a voltagestanding wave ratio (VSWR), and 3D antenna patterns according to anembodiment of the present invention.

FIG. 7A and FIG. 7B show ranging according to the related art.

FIG. 8 shows a vertical distance between a tag and an anchor accordingto another embodiment of the present invention.

FIG. 9 shows a ranging method using a UWB system according to anotherembodiment of the present invention.

FIG. 10A to FIG. 10C show antenna diversity.

FIG. 11 shows double-sided two-way ranging (DS-TWR) according to therelated art.

FIGS. 12 to 14 show reception performance according to anotherembodiment of the present invention.

FIG. 15 shows two-way ranging according to another embodiment of thepresent invention.

FIG. 16 shows an antenna diversity implementation method using a UWBsystem according to still another embodiment of the present invention.

FIG. 17 shows a UWB module driven for each operation scenario accordingto still another embodiment of the present invention.

FIG. 18A and FIG. 18B show primary and secondary operations of a UWBmodule upon driver seat passive keyless entry (PKE) operation accordingto still another embodiment of the present invention.

FIGS. 19 to 21 show a UWB ranging method according to still anotherembodiment of the present invention.

FIG. 22 shows a UWB operation environment according to the related art.

FIG. 23 shows a UWB system using a sniffing result according to stillanother embodiment of the present invention.

FIG. 24 illustrates a UWB operation method using a sniffing resultaccording to still another embodiment of the present invention.

FIG. 25 shows a distance-based UWB system according to still anotherembodiment of the present invention.

FIG. 26 shows a distance-based UWB operation method according to stillanother embodiment.

FIG. 27 shows a UWB ranging sequence that is defined by the CarConnectivity Consortium (CCC) standard on the basis of four anchors.

FIG. 28 shows a UWB system using a UWB ranging factor definitionaccording to still another embodiment of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

These and other objects, advantages and features of the presentinvention, and implementation methods thereof will be clarified throughthe following embodiments described with reference to the accompanyingdrawings.

The present invention may, however, be embodied in different forms andshould not be construed as being limited to the embodiments set forthherein. Rather, these embodiments are provided so that this disclosurewill fully convey the objects, configurations, and effects of thepresent invention to those skilled in the art. The scope of the presentinvention is defined solely by the appended claims.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting to the invention. Asused herein, the singular forms “a,” “an,” and “one” include the pluralunless the context clearly indicates otherwise. The terms “comprise”and/or “comprising,” when used in this specification, specify thepresence of stated elements, steps, operations, and/or components, butdo not preclude the presence or addition of one or more other elements,steps, operations, and/or components.

The background of the present invention will be described first beforeembodiments of the present invention are described.

UWB is a technology that calculates a distance between entities bymultiplying a signal arrival time between communication entities by thespeed of light using a time-of-flight (ToF) technique of ultra-wideband(6 to 8 GHz with a bandwidth of over 500 MHz).

In the related art, time-slotted channel hopping (TSCH) is channelhopping that is continuously repeated over time. In some cases, thechannel hopping causes continuous communication interference dependingon the operation period.

In the related art, a smart key (SMK) system uses low frequency (LF; 125kHz) and radio frequency (RF; 434 MHz) techniques to determine theposition of a smart key fob, control locking and unlocking of a vehicledoor, and start a vehicle.

UWB is a technology that calculates a distance between entities bymultiplying a signal arrival time between communication entities by thespeed of light using a time-of-flight (ToF) technique.

According to the related art, even when a UWB antenna radiation patternis designed as uniformly as possible, null points may be generated inthe radiation pattern due to unpredictable factors such as vehicleenvironments and surrounding environments.

In order to solve this problem, diversity may be implemented bydesigning a plurality of antennas. However, this method is inefficientin that ranging needs to be performed twice.

Also, according to the related art, there are problems in terms of powerconsumption and speed because several anchors continuously performranging on a distant tag.

Precise positioning is required when a tag is at a short distance (e.g.,less than two meters around a vehicle) but is not required when a tag isfar away.

In order to provide location-based services (LBS), technologies such asa Global Positioning System (GPS), Wi-Fi, and Bluetooth have been used.There is a problem in that precise measurement is difficult, but UWB (6to 8 GHz with a bandwidth of over 500 MHz) has a wide frequency band,low power consumption, and high-accuracy positioning within tens ofcentimeters.

In the related art, GPS-based and mobile communication network-basedpositioning technologies have an error range of 5 to 50 meters and anerror range of 50 to 200 meters, respectively. In the case of GPS, afailure may occur while signals from satellites reach an urban buildingarea.

In the case of Wi-Fi, positioning is possible at low cost, but since thefrequency band used is narrow, there may be a limit to channel divisionwhen the number of tracking targets increases. Also, mobile terminalsmay be disconnected from a stationary Wi-Fi access point (AP).

In the case of Bluetooth, it is possible to deploy a large number ofsensors at low cost, but since communication latency is high, thistechnology is not suitable for real-time positioning in a dynamicenvironment.

Unlike Wi-Fi and Bluetooth, in the case of UWB, a wide frequency band isused, and it is possible to transmit a large amount of information at ahigh transmission rate and with low power.

Advantageously, UWB technology-based positioning exhibits a low errorrate of about 20 cm, has high transmittance to an obstacle, and is notaffected by other signals such as a Wi-Fi signal.

FIG. 1 illustrates a problem of time-slotted channel hopping (TSCH) inthe related art.

Referring to a first UWB session of a first vehicle and a second UWBsession of a second vehicle, the first vehicle and the second vehiclecontinue time-hopping, but frequency interference occurs continuously insome cases (according to the period).

FIG. 2 shows a UWB module application band.

The UWB module application band is used for smart key hacking (RSA)defense and digital key (smartphone) positioning.

Channel 5 has a center frequency of 6.5 GHz and a bandwidth of 499.2MHz, and Channel 9 has a center frequency of 8.0 GHz and a bandwidth of499.2 MHz.

In addition to the two cases, that is, smart key hacking defense anddigital key positioning, various UWB technologies may be applied tovehicles.

For example, a UWB technology for detecting a passenger in a vehicle, aUWB technology for detecting a parking area and notifying a user ofdanger, and a UWB technology for providing convenience functions(automatic trunk opening, etc.) according to the detection of a user'smotion (a kick sensor, etc.) may be applied, and the risk of frequencyinterference increases as the type of USB communication applicable tovehicles becomes diversified.

FIG. 3 shows a UWB system according to an embodiment of the presentinvention.

The UWB system according to an embodiment of the present inventionincludes a memory 101 in which a UWB communication program is embeddedand a processor 102 which executes the program. The processor 102performs UWB time-hopping and frequency-hopping to establish acommunication channel.

The processor 102 performs UWB operation and activates a hopping timer.

The processor 102 performs time-hopping to avoid signal interference andcalculates a hopping count.

The processor 102 determines whether the count value exceeds a firstpreset value and whether the timer has a value less than a second presetvalue.

When the count value does not exceed the first preset value or when thetimer has a value not less than the second preset value, the processor102 continues to perform the time-hopping.

When the count value exceeds the first preset value and the timer has avalue less than the second preset value, the processor 102 performsfrequency-hopping.

After the frequency-hopping, the processor 102 starts the UWB operationand starts the hopping timer.

The processor 102 performs time-hopping to avoid signal interference andcalculates a hopping count.

The processor 102 determines whether the count value exceeds a thirdpreset value and whether the timer has a value less than a fourth presetvalue.

In this case, the first preset value and the third preset value may beset to the same value or different values. Likewise, the second presetvalue and the fourth preset value may be set to the same value ordifferent values.

The first preset value and the third preset value may be set to bedifferent depending on the communication conditions (the number ofnearby communication devices) or the number of times of hopping.

For example, the processor 102 may perform frequency-hopping for thefirst time after time-hopping is performed once, performfrequency-hopping for the second time after time-hopping is performedtwo times, and perform frequency-hopping for the third time aftertime-hopping is performed three times.

When the count value does not exceed the third preset value or when thetimer has a value not less than the fourth preset value, the processor102 continues to perform the time-hopping.

When the count value exceeds the third preset value and the timer has avalue less than the fourth preset value, the processor 102 performsfrequency-hopping.

FIG. 4 shows frequency-hopping according to an embodiment of the presentinvention.

In channel 5, the first UWB session of the first vehicle and the secondUWB session of the second vehicle still have interference despitetime-hopping. Accordingly, channel 5 is busy.

In order to avoid such repeated signal interference, frequency-hoppingis performed on the second UWB session of the second vehicle. As aresult, smooth communication is possible in both channels 5 and 9.

FIG. 5 illustrates a UWB operation method according to an embodiment ofthe present invention.

The UWB operation method according to an embodiment of the presentinvention includes performing UWB operation and operating a hoppingtimer, performing time-hopping and monitoring interference situationinformation, and performing frequency-hopping according to a result ofmonitoring the interference situation information.

Referring to FIG. 5 , the method includes performing UWB operation andactivating a hopping timer (S501).

The method includes performing time-hopping to avoid signal interference(S502) and calculating hopping count (S503).

The method includes determining whether the count value exceeds a firstpreset value (S504) and determining whether the timer has a value lessthan a second preset value (S505).

The method includes continuing the time-hopping in S502 when the countvalue does not exceed the first preset value in S504 or when the timerhas a value not less than the second preset value in S505.

The method includes performing frequency-hopping (S506) when the countvalue exceeds the first preset value in S504 and the timer has a valueless than the second preset value in S505.

The method includes starting the UWB operation and starting the hoppingtimer (S507) after the frequency-hopping.

The method includes performing time-hopping to avoid signal interference(S508) and calculating a hopping count (S509).

The method includes determining whether the count value exceeds a thirdpreset value (S510) and determining whether the timer has a value lessthan a fourth preset value (S511).

In this case, the first preset value and the third preset value may beset to the same value or different values. Likewise, the second presetvalue and the fourth preset value may be set to the same value ordifferent values.

The first preset value and the third preset value may be set to bedifferent depending on the communication conditions (the number ofnearby communication devices) or the number of times of hopping.

For example, frequency-hopping is performed for the first time aftertime-hopping is performed once, is performed for the second time aftertime-hopping is performed two times, and is performed for the third timeafter time-hopping is performed three times.

The method includes continuing the time-hopping (S508) when the countvalue does not exceed the third preset value in S510 or when the timerhas a value not less than the fourth preset value in S511.

The method includes performing frequency-hopping (S506) when the countvalue exceeds the third preset value in S510 and the timer has a valueless than the fourth preset value in S511.

FIG. 6 illustrates UWB modeling, UWB antenna specifications, a voltagestanding wave ratio (VSWR), and 3D antenna patterns according to anembodiment of the present invention.

A UWB antenna has an efficiency of 84.91%, an average gain of −0.71 dBi,and a peak gain of 3.48 dBi at 6.5 GHz and an efficiency of 83.76%, anaverage gain of −0.76 dBi, and a peak gain of 3.38 dBi at 8.0 GHz.

Referring to FIG. 6 , VSWR and 3D antenna patterns are shown.

FIG. 7A and FIG. 7B show, as a two-way ranging (TWR) scheme,double-sided (DS) TWR and single-sided (SS) TWR.

Ranging refers to an action of measuring a distance between one fob andone anchor. A data structure conforms to the IEEE802.15.4z standard andtakes about 200 us per packet transmission.

A slot is defined as the time it takes for the fob or anchor to transmit(or receive) a signal again after transmitting (or receiving) a signal.

UWB transmission/reception slot of an RSA defense SMK system may bedesigned as about 2 ms and may be changed depending on thespecification.

The DS-TWR scheme consumes a great deal of power due to the large numberof signals that are transmitted and received but has excellent distancemeasurement accuracy.

A fob transmits a poll packet and records a timestamp T0.

An anchor receives a poll packet and records T1.

The anchor requires time Td1 to receive a signal and generate a responsepacket, transmits a response message, and records T2.

The fob receives the response message and records T3.

The fob requires time Td2 to receive a signal and generate a finalmessage.

The fob transmits the final message and records T4, and the anchorreceives the final message and records T5.

As described above, DS-TWR has an accurate ranging result, but thisscheme calculates a distance using two round-trip times, so thecalculation formula is complex and power consumption is relativelylarge.

TWR calculates a distance using one round-trip time, so the calculationformula is relatively simple and power consumption is relatively lowwhile the ranging error is large compared to DS-TWR.

However, an error at a distance is acceptable within a certain range,and it is necessary to apply a technology to reduce power consumptionduring long ranging.

FIG. 8 shows a vertical distance between a tag and an anchor accordingto another embodiment of the present invention.

The distance between a first anchor 300 a and a fourth anchor 300 d andthe distance between a second anchor 300 b and a third anchor 300 c are3 meters, and these are preset during the developing stage.

A distance between a vehicle and a tag (a first tag 200 a is a fob and asecond tag 200 b is a smartphone) is generally defined as a verticaldistance (the length of a perpendicular line).

The first tag 200 a is 4 meters away from the first anchor 300 a, is 5meters away from the fourth anchor 300 d, and has a vertical distance of4 meters.

That is, the vertical distance is equal to 4 meters, which is thedistance from the first tag 200 a to the first anchor 300 a, which isthe nearest anchor.

The second tag 200 b is 4.1 meters away from the second anchor 300 b, is3.9 meters away from the third anchor 300 c, and has a vertical distanceof 3.7 meters.

That is, the vertical distance has a difference of 0.2 meters comparedto 3.9 meters, which is the distance from the second tag 200 b and thethird anchor 300 c, which is the nearest anchor, and the distance is notlarge.

When a tag is located at a short distance, such as within 2 meters, fromthe vehicle, precise positioning is necessary, but when there is a tagat a long distance, precise positioning is unnecessary.

However, when several anchors continuously perform ranging on a remotetag, there are problems in terms of power consumption and operationtime.

A UWB system according to another embodiment of the present inventionincludes an input unit configured to receive information on a separationdistance between a tag and a vehicle, a memory in which a rangingprogram corresponding to the separation distance is embedded, and aprocessor which executes the program, wherein the program determines aranging scheme and an anchor to perform ranging according to theseparation distance.

The input unit receives information regarding a vertical distancebetween the tag and the vehicle.

When the separation distance is greater than or equal to a first setdistance, the processor performs SS-TWR using an anchor of the vehicleclosest to the tag.

When the separation distance is greater than or equal to a second setdistance and is less than the first set distance, the processor performsDS-TWR using an anchor of the vehicle closest to the tag.

When the separation distance is greater than or equal to a third setdistance and is less than the second set distance, the processorperforms SS-TWR using a plurality of anchors.

When the separation distance is less than the third set distance, theprocessor performs DS-TWR using a plurality of anchors.

FIG. 9 shows a ranging method using a UWB system according to anotherembodiment of the present invention.

In S901, the UWB system determines a separation distance D between a tagand a vehicle. In this case, the separation distance D is a verticaldistance.

In S902, the UWB system determines whether the separation distance isgreater than or equal to a first set distance (e.g., 10 meters) (S913).

When it is determined in S902 that the separation distance is greaterthan or equal to the first set distance, the UWB system performs SS-TWRusing one anchor nearest to the tag (S903).

In S904, the UWB system determines whether the separation distance isgreater than or equal to a second set distance (e.g., 6 meters).

When it is determined in S904 that the separation distance is greaterthan or equal to the second set distance, the UWB system performs DS-TWRusing one anchor nearest to the tag (S905).

In S906, the UWB system determines whether the separation distance isgreater than or equal to a third set distance (e.g., 3 meters).

When it is determined in S906 that the separation distance is greaterthan or equal to the third set distance, the UWB system performs SS-TWRusing a plurality of anchors (S907).

When SS-TWR is performed using a plurality of anchors, power consumptionis greater and positioning accuracy is higher than when DS-TWR isperformed using one anchor.

When it is determined in S906 that the separation distance is less thanthe third set distance, the UWB system performs DS-TWR using a pluralityof anchors (S908).

The UWB system determines a separation distance D in S909 and determineswhether the separation distance is less than the second set distance(e.g., 6 meters) in S910.

When it is determined in S910 that the separation distance is less thanthe second set distance, the UWB system performs DS-TWR using aplurality of anchors (S908).

When it is determined in S910 that the separation distance is greaterthan or equal to the second set distance, the UWB system determineswhether the separation distance is greater than or equal to the secondset distance (e.g., 6 meters) and is less than the first set distance(e.g., 10 meters) in S911.

When it is determined in S911 that the separation distance is greaterthan or equal to the second set distance and is less than the first setdistance, the UWB system performs SS-TWR using a plurality of anchors(S912) and returns to operation S909 to determine a separation distance.

When the UWB system determines that a condition is not satisfied inS911, the UWB system determines whether the separation distance isgreater than or equal to the first set distance (e.g., 10 meters).

When it is determined in S913 that the separation distance is greaterthan or equal to the first set distance, the UWB system performs DS-TWRusing one anchor nearest to the tag (S914).

According to another embodiment of the present invention, when thedistance between the tag and the vehicle decreases and then increases,the number of anchors and a TWR type are determined by criteriadifferent from those when the distance between the tag and the vehicledecreases.

FIG. 10A to FIG. 10C show antenna diversity.

Even though a UWB antenna radiation pattern is designed as uniformly aspossible, null points may be generated in the radiation pattern due tounpredictable factors such as vehicle environments and surroundingenvironments.

In order to solve this problem, it is possible to implement diversity bydesigning a plurality of antennas.

FIG. 10A shows the radiation pattern of a first antenna, and FIG. 10Bshows the radiation pattern of a second antenna.

As shown in FIG. 10C, it is possible to implement diversity through theintegrated radiation pattern of the first antenna and the secondantenna.

When the UWB antenna diversity is implemented, reception sensitivity isimproved, but the cost of implementing switching elements and antennasincreases, and the module size increases. Also, ranging has to berepeated.

FIG. 11 shows a DS-TWR process according to the related art. In theDS-TWR process, two antennas are used to implement antenna diversity.Upon DS-TWR activation based on four anchors, 12 slots are needed.

FIGS. 12 to 14 show reception performance according to still anotherembodiment of the present invention, and FIG. 15 shows two-way rangingaccording to still another embodiment of the present invention.

A UWB system according to still another embodiment of the presentinvention includes an input unit for receiving a poll packet from a fob,a memory in which a program for performing ranging is embedded, and aprocessor which executes the program, wherein the processor selects abetter antenna for each anchor from among a plurality of antennasapplied to implement antenna diversity and performs ranging using theselected antenna.

The input unit receives a poll packet from the fob multiple times.

The processor selects a better antenna by using the signal strength ofreceived data.

The processor transmits a response to the fob using the selectedantenna.

The processor receives a final message from the fob using the selectedantenna.

FIG. 12 shows reception performance when only a first antenna is used,FIG. 13 shows reception performance when only a second antenna is used,and FIG. 14 shows reception performance when diversity is implemented(dotted line arrows indicate poor reception performance and solid linearrows indicate good reception performance).

When the first and second antennas are provided to implement antennadiversity, a poll is transmitted from a fob to an anchor two times (apoll for the first antenna and a poll for the second antenna) in orderto find the one with higher performance between the first antenna andthe second antenna.

An antenna with high performance may be different for each anchor everyranging (poll-response-final).

That is, referring to FIGS. 12 to 14 , the second antenna is better fora first anchor 300 a and a second anchor 300 b, and the first antenna isbetter for a third anchor 300 c and a fourth anchor 300 d.

Each anchor transmits a response to a fob 200 using the better antenna.

Each anchor uses the signal strength of received data (received signalstrength indicator (RSSI)) to select its suitable antenna and determinesthat the accuracy of data increases as the signal strength increases.

When the fob 200 transmits a final message (Final), each anchor stillreceives the final message using the selected antenna.

FIG. 15 shows “Response(TRx #1) Using better Ant (1 or 2),” andaccording to the above example, a first anchor 300 a (TRx #1) transmitsa response using the second antenna.

FIG. 15 shows “Response(TRx #2) Using better Ant (1 or 2),” andaccording to the above example, a second anchor 300 b (TRx #2) transmitsa response using the second antenna.

FIG. 15 shows “Response(TRx #3) Using better Ant (1 or 2),” andaccording to the above example, a third anchor 300 c (TRx #3) transmitsa response using the first antenna.

FIG. 15 shows “Response(TRx #4) Using better Ant (1 or 2),” andaccording to the above example, a fourth anchor 300 d (TRx #4) transmitsa response using the first antenna.

As shown in FIG. 15 , according to an embodiment of the presentinvention, when DS-TWR is performed based on four anchors, seven oreight slots are needed.

In the case of applying the diversity of UWB antennas, generally, thesame ranging is repeated to reduce the probability of missing data. Inthis case, however, as described above, 12 slots are needed.

That is, in the case of using four anchors, when one antenna is used,six slots are required, but when two antennas apply antenna diversity,twelve slots, which is twice as many, are required.

However, according to still another embodiment of the present invention,only a poll is transmitted two times, and only a better antenna isselected in consideration of the reliability (e.g., signal strength) oftwo pieces of received data.

Since each anchor performs the next ranging through the selectedantenna, finally, only one slot needs to be added, and it is possible toimprove reception sensitivity with seven slots.

According to still another embodiment of the present invention, byreducing the number of slots that increase power consumption andoperation time, it is possible to improve performance.

FIG. 16 shows an antenna diversity implementation method using a UWBsystem according to still another embodiment of the present invention.

An anchor receives a poll packet from a fob (S1610).

The anchor selects a better antenna from among a plurality of antennasapplied to implement antenna diversity according to a result ofreceiving the poll packet (S1620).

The anchor performs ranging by transmitting a response using the antennaselected in S1620 (S1630).

After S1630, the anchor receives a final message transmitted from thefob using the selected antenna.

When first and second antennas are provided to implement antennadiversity, a poll is transmitted from a fob to an anchor two times (thepoll for the first antenna and the poll for the second antenna) in orderto find the one with higher performance between the first antenna andthe second antenna, and the anchor receives the poll packet in S1610.

In S1620, the anchor uses the signal strength of received data (RSSI) toselect the better antenna.

Referring to FIGS. 12 to 14 , each anchor has a different antenna withhigh performance. The second antenna is better for the first anchor 300a and the second anchor 300 b, and the first antenna is better for thethird anchor 300 c and the fourth anchor 300 d.

In S1630, each anchor transmits a response to the fob 200 using thebetter antenna. That is, the first anchor 300 a and the second anchor300 b transmit a response using the second antenna, and the third anchor300 c and the fourth anchor 300 d transmit a response using the firstantenna.

After S1630, when the fob transmits a final message (Final), each anchorreceives the final message still using the selected antenna.

A UWB ranging control device according to still another embodiment ofthe present invention includes a memory in which a UWB ranging programis embedded and a processor which executes the program, wherein theprogram extracts a combination of UWB anchors mounted on a vehicle foreach operation scenario and performs control such that a rangingoperation is performed according to priorities.

The processor extracts a combination for each operation scenariocorresponding to driver seat passive keyless entry (PKE), passenger seatPKE, passive trunk, and passive start and transmits a wake-up signal.

The processor performs control such that primary ranging is performedusing a UWB anchor for which it is determined to be easy to find adevice for each operation scenario and which is given a higher priority.When the ranging result is a failure, the processor performs controlsuch that secondary ranging is sequentially performed using a UWB anchorwhich is given a lower priority.

The processor determines whether to perform RSA using at least one ofthe result of the primary ranging and the result of the secondaryranging and determines whether to perform the operation.

FIG. 17 shows a UWB module driven for each operation scenario accordingto still another embodiment of the present invention.

A vehicle is equipped with first to seventh UWB modules 210 to 270. Thefirst UWB module 210, the second UWB module 220, the third UWB module230, and the fourth UWB module 240 are installed on a bumper outside thevehicle, and the fifth UWB module 250, the sixth UWB module 260, and theseventh UWB module 270 are installed in the vehicle (e.g., a roof).

According to the related art, only four UWB modules installed outsidethe vehicle are used, but according to an embodiment of the presentinvention, the combination of driven UWB modules is different dependingon the usage scenario.

Upon driver seat PKE operation, the first UWB module 210, the fourth UWBmodule 240, the fifth UWB module 250, and the seventh UWB module 270 aredriven.

Upon passenger seat PKE operation, the second UWB module 220, the thirdUWB module 230, the fifth UWB module 250, and the sixth UWB module 260are driven.

Upon passive trunk operation, the third UWB module 230, the fourth UWBmodule 240, the sixth UWB module 260, and the seventh UWB module 270 aredriven.

Upon passive start operation, the first UWB module 210, the fifth UWBmodule 250, the sixth UWB module 260, and the seventh UWB module 270 aredriven.

That is, according to still another embodiment of the present invention,four UWB modules are driven. At this point, the most necessary UWBmodules are selectively driven depending on the driver seat PKE, passivetrunk, and passive start scenarios.

FIG. 18A and FIG. 18B show primary and secondary operations of a UWBmodule upon driver seat PKE operation.

According to still another embodiment of the present invention, thefirst UWB module 210, the fourth UWB module 240, the fifth UWB module250, and the seventh UWB module 270 are driven as described above. TheseUWB modules are not activated all at once, but are divisionally drivenin primary and secondary operations in consideration of optimization interms of power and time.

First, referring to FIG. 18A, first, the first UWB module 210 and thefourth UWB module 240 perform ranging as the primary operation. When adevice (UWB fob) 300 is found in a certain region, the correspondingoperation is completed.

Referring to FIG. 18B, the fifth UWB module 250 and the seventh UWBmodule 270 perform additional ranging as the secondary operation whenthe ranging of the first UWB module 210 and the fourth UWB module 240fails for any reason during the primary operation process.

Since the above-described sequential primary and secondary operationsare directed to a device approaching from the side of the bumper duringthe driver seat PKE, a UWB module corresponding to conditions in whichit is easiest to find the device is operated first.

Also, in special cases (e.g., when a vehicle is surrounded by manypeople), ranging using the first UWB module 210 and the fourth UWBmodule 240 placed on the bumper is not possible. In this case, rangingis performed using the fifth UWB module 250 and the seventh UWB module270 mounted on the inner roof of the vehicle and configured to view fromthe top down.

FIGS. 19 to 21 show a UWB ranging method according to still anotherembodiment of the present invention.

Referring to FIG. 19 , the UWB ranging method according to still anotherembodiment of the present invention includes extracting a combination ofUWB anchors installed in a vehicle for each operation scenario (S1910),performing primary ranging using the UWB anchor with a higher priorityincluded in the extracted combination of UWB anchors (S1920), andperforming secondary ranging using the UWB anchors with a lower priorityincluded in the extracted combination of UWB anchors (S1930).

In S1910, the UWB ranging method includes extracting a combination foreach operation scenario corresponding to driver seat PKE, passenger seatPKE, passive trunk, and passive start.

In S1920, the UWB ranging method includes performing primary rangingusing a UWB anchor for which it is determined to be easy to find adevice for each operation scenario and which is given a higher priorityand transmitting a result of the ranging to an integrated control unit.

In S1930, the UWB ranging method includes performing secondary rangingusing a UWB anchor given a lower priority when the ranging result is afail in S1920.

Referring to FIG. 20 , first, the UWB ranging method includesdetermining a passive situation (S2001). Each operation is performeddifferently according to the four operation scenarios. In this case, ananchor driven for each operation may be changed due to a factor such asa vehicle layout, etc.

Upon driver seat PKE operation (S2010), the UWB ranging method includestransmitting activation (wake-up) signals for the first UWB module 210,the fourth UWB module 240, the fifth UWB module 250, and the seventh UWBmodule 270 (S2011).

Subsequently, the UWB ranging method includes, as the primary operation,performing ranging using the first UWB module 210 and the fourth UWBmodule 240 and determining whether an RSA condition corresponding to aresult of the ranging is satisfied (S2012).

When it is determined in S2012 that the condition corresponding to theranging result is satisfied, the UWB ranging method includes determiningthat RSA is not applied and terminating the processing after normaloperation (S2014).

When it is determined in S2012 that the condition corresponding to theranging result is not satisfied, the UWB ranging method includes, as thesecondary operation, performing ranging using the fifth UWB module 250and the seventh UWB module 270 and determining whether an RSA conditioncorresponding to a result of the ranging is satisfied (S2013).

When it is determined in S2013 that the condition corresponding to theranging result is satisfied, the UWB ranging method includes determiningthat RSA is not applied and terminating the processing after normaloperation (S2014). When it is determined in S2013 that the conditioncorresponding to the ranging result is not satisfied, the UWB rangingmethod includes performing RSA defense and terminating the processingwithout any operation (S2015).

Upon passenger seat PKE operation (S2020), the UWB ranging methodincludes transmitting activation (wake-up) signals for the second UWBmodule 220, the third UWB module 230, the fifth UWB module 250, and thesixth UWB module 260 (S2021).

Subsequently, the UWB ranging method includes, as the primary operation,performing ranging using the second UWB module 220 and the third UWBmodule 230 and determining whether an RSA condition corresponding to aresult of the ranging is satisfied (S2022).

When it is determined in S2022 that the condition corresponding to theranging result is satisfied, the UWB ranging method includes determiningthat RSA is not applied and terminating the processing after normaloperation (S2024).

When it is determined in S2022 that the condition corresponding to theranging result is not satisfied, the UWB ranging method includes, as thesecondary operation, performing ranging using the fifth UWB module 250and the sixth UWB module 260 and determining whether an RSA conditioncorresponding to a result of the ranging is satisfied (S2023).

When it is determined in S2023 that the condition corresponding to theranging result is satisfied, the UWB ranging method includes determiningthat RSA is not applied and terminating the processing after normaloperation (S2024). When it is determined in S2023 that the conditioncorresponding to the ranging result is not satisfied, the UWB rangingmethod includes performing RSA defense and terminating the processingwithout any operation (S2025).

Upon passive trunk operation (S2030), the UWB ranging method includestransmitting activation (wake-up) signals for the third UWB module 230,the fourth UWB module 240, the sixth UWB module 260, and the seventh UWBmodule 270 (S2031).

Subsequently, the UWB ranging method includes, as the primary operation,performing ranging using the third UWB module 230 and the fourth UWBmodule 240 and determining whether an RSA condition corresponding to aresult of the ranging is satisfied (S2032).

When it is determined in S2032 that the condition corresponding to theranging result is satisfied, the UWB ranging method includes determiningthat RSA is not applied and terminating the processing after normaloperation (S2034).

When it is determined in S2032 that the condition corresponding to theranging result is not satisfied, the UWB ranging method includes, as thesecondary operation, performing ranging using the sixth UWB module 260and the seventh UWB module 270 and determining whether an RSA conditioncorresponding to a result of the ranging is satisfied (S2033).

When it is determined in S2033 that the condition corresponding to theranging result is satisfied, the UWB ranging method includes determiningthat RSA is not applied and terminating the processing after normaloperation (S2034). When it is determined in S2033 that the conditioncorresponding to the ranging result is not satisfied, the UWB rangingmethod includes performing RSA defense and terminating the processingwithout any operation (S2035).

Upon passive start operation (S2040), the UWB ranging method includestransmitting activation (wake-up) signals for the first UWB module 210,the fifth UWB module 250, the sixth UWB module 260, and the seventh UWBmodule 270 (S2041).

Subsequently, the UWB ranging method includes, as the primary operation,performing ranging using the fifth UWB module 250 and the sixth UWBmodule 260 and determining whether an RSA condition corresponding to aresult of the ranging is satisfied (S2042).

When it is determined in S2042 that the condition corresponding to theranging result is satisfied, the UWB ranging method includes determiningthat RSA is not applied and terminating the processing after normaloperation (S2044).

When it is determined in S2042 that the condition corresponding to theranging result is not satisfied, the UWB ranging method includes, as thesecondary operation, performing ranging using the first UWB module 210and the seventh UWB module 270 and determining whether the RSA conditioncorresponding to the ranging result is satisfied (S2043).

When it is determined in S2043 that the condition corresponding to theranging result is satisfied, the UWB ranging method includes determiningthat RSA is not applied and terminating the processing after normaloperation (S2044). When it is determined in S2043 that the conditioncorresponding to the ranging result is not satisfied, the UWB rangingmethod includes performing RSA defense and terminating the processingwithout any operation (S2045).

Referring to FIG. 21 , it is assumed that first to fourth anchors 510 to540 are anchors corresponding to an optimal combination that is drivenaccording to an operation scenario.

An integrated control unit 100 transmits a wake-up signal and rangingsignals for the first anchor 510 and the second anchor 520 (S2101).

Ranging is performed between the device 300 and the first anchor 510(S2102) and between the device 300 and the second anchor 520 (S2103),the first anchor 510 transmits a ranging result of the first anchor 510to the integrated control unit 100 (S2104), and the second anchor 520transmits a ranging result of the second anchor 520 to the integratedcontrol unit 100 (S2105).

The integrated control unit 100 determines whether RSA condition 1 issatisfied using the ranging result of the first anchor 510 and theranging result of the second anchor 520 (S2106).

Subsequently, the integrated control unit 100 transmits ranging signalsfor the third anchor 530 and the fourth anchor 540 (S2107).

Ranging is performed between the device 300 and the third anchor 530(S608) and between the device 300 and the fourth anchor 540 (S609), thethird anchor 530 transmits a ranging result of the third anchor 530 tothe integrated control unit 100 (S2110), and the fourth anchor 540transmits a ranging result of the fourth anchor 540 to the integratedcontrol unit 100 (S2111).

The integrated control unit 100 determines whether RSA condition 2 issatisfied using the ranging result of the third anchor 530 and theranging result of the fourth anchor 540 (S2112).

FIG. 22 shows a UWB operation environment according to the related art.

In an environment with many vehicles, the UWB communication of Tag1 isaffected by surroundings thereof, and thus an inaccurate ranging resultis derived.

In this case, the surrounding influences include an influence due to asteel component of a nearby vehicle, an influence due to a wirelesscommunication noise component, and the like.

In an environment with no vehicles, the UWB communication of Tag2 is notaffected by surroundings, and thus a relatively accurate ranging resultis derived.

FIG. 23 shows a UWB system using a sniffing result according to stillanother embodiment of the present invention.

The UWB system according to still another embodiment of the presentinvention includes a memory 103 with a program for performing UWBranging by referring to the sniffing result and a processor 104 thatexecutes the program, and the processor 104 changes the UWB rangingmethod or changes the UWB ranging period in consideration of thesniffing result.

The processor 104 performs UWB ranging in the SS-TWR scheme, monitorsthe sniffing result, and determines whether the sniffing result exceedsa first preset value.

When it is determined that the sniffing result does not exceed the firstpreset value, the processor 104 continues to perform the UWB ranging inthe SS-TWR scheme.

When it is determined that the sniffing result exceeds the first presetvalue, the processor 104 determines whether the sniffing result exceedsa second preset value.

When it is determined that the sniffing result does not exceed thesecond preset value, the processor 104 changes the UWB ranging method tothe DS-TWR scheme and performs UWB ranging in the DS-TWR scheme.

When it is determined that the sniffing result exceeds the second presetvalue, the processor 104 changes the period of the UWB ranging andperforms the UWB ranging in the DS-TWR scheme. For example, theprocessor 104 halves the period of the UWB ranging.

According to still another embodiment of the present invention, in orderto determine surrounding environment information of a vehicle with whicha tag communicates, the environment information is predicted throughwireless communication sniffing, and the sniffing is defined as aprocess of monitoring and capturing all packets passing through adesignated network.

The medium of the sniffing may be various wireless communication schemes(e.g., Bluetooth Low Energy (BLE), UWB, Wi-Fi, etc.), and a wirelesscommunication scheme used in more vehicles can predict a surroundingenvironment more accurately.

According to an embodiment of the present invention, by distinguishing acase in which the surrounding environment is not good and a case inwhich the surrounding environment is good and by changing a UWB rangingperiod and method, it is possible to minimize power consumption andenable precise positioning.

FIG. 24 shows a UWB operation method using a sniffing result accordingto still another embodiment of the present invention.

The UWB operation method according to still another embodiment of thepresent invention includes (a) monitoring a sniffing result whileperforming UWB ranging and (b) changing a UWB ranging method or changinga UWB ranging period depending on the sniffing result.

Referring to FIG. 24 , the UWB operation method includes performing theUWB ranging in the SS-TWR scheme (S2401).

The UWB operation method includes monitoring the sniffing result anddetermining whether the sniffing result exceeds a first preset value(S2402).

When it is determined in S2402 that the sniffing result does not exceedthe first preset value, the UWB operation method includes continuing toperform the UWB ranging in the SS-TWR scheme (S2401).

When it is determined in S2402 that the sniffing result exceeds thefirst preset value, the UWB operation method includes determiningwhether the sniffing result exceeds a second preset value (S2403).

When it is determined in S2403 that the sniffing result does not exceedthe second preset value, the UWB operation method includes performingUWB ranging in the DS-TWR scheme (S2404).

When it is determined in S2403 that the sniffing result exceeds thesecond preset value, the UWB operation method includes changing theperiod of the UWB ranging and performing the UWB ranging in the DS-TWRscheme (S2405).

In this case, for example, the period of the UWB ranging is halved.

FIG. 25 shows a distance-based UWB system according to still anotherembodiment of the present invention.

A distance-based UWB system according to still another embodiment of thepresent invention includes a memory 105 in which a ranging programcorresponding to a separation distance between a tag and a vehicle isembedded and a processor 106 which executes the program, wherein theprocessor 106 determines an anchor to perform ranging and a rangingscheme according to the separation distance.

When the separation distance is less than a first preset distance, theprocessor 106 performs ranging in the DS-TWR scheme using N anchors.

When the separation distance is greater than or equal to the firstpreset distance and is less than a second preset distance, the processor106 performs ranging in the DS-TWR scheme using an anchor of a vehicleclosest to the tag.

When the separation distance is greater than or equal to the secondpreset distance, the processor 106 performs ranging in the SS-TWR schemeusing an anchor of a vehicle closest to the tag.

FIG. 26 shows a distance-based UWB operation method according to stillanother embodiment.

The distance-based UWB operation method according to still anotherembodiment of the present invention is a UWB ranging method in the casein which a tag becomes far away.

A distance-based UWB operation method according to still anotherembodiment of the present invention includes (a) receiving informationregarding a separation distance between a tag and a vehicle and (b)determining an anchor to perform ranging and a ranging scheme accordingto the separation distance.

In operation (a), the distance-based UWB operation method includesreceiving information regarding a vertical distance between a tag and avehicle.

In operation (b), when the separation distance is less than a firstpreset distance, the distance-based UWB operation method includesperforming ranging in the DS-TWR scheme using N anchors.

In operation (b), when the separation distance is greater than or equalto the first preset distance and is less than a second preset distance,the distance-based UWB operation method includes performing ranging inthe DS-TWR scheme using an anchor of a vehicle closest to the tag.

In operation (b), when the separation distance is greater than or equalto the second preset distance, the distance-based UWB operation methodincludes performing ranging in the SS-TWR scheme using an anchor of avehicle closest to the tag.

When the tag approaches, UWB ranging is performed in a more accuratescheme according to an application.

Referring to FIG. 26 , the distance-based UWB operation method includesperforming ranging in the DS-TWR scheme using N anchors within a firstpreset distance (e.g., 3 meters) in S2601.

Referring to FIG. 26 , the distance-based UWB operation method includesdetermining whether the vertical distance is greater than or equal to afirst preset distance (e.g., 3 meters) in S2602.

When it is determined in S2602 that the vertical distance is less thanthe first preset distance, the distance-based UWB operation methodincludes continuing to perform ranging in the DS-TWR scheme using Nanchors in S2603.

The distance-based UWB operation method includes determining whether thevertical distance is greater than or equal to the second preset distance(e.g., 6 meters) in S2604.

When it is determined in S2604 that the vertical distance is less thanthe second preset distance, that is, when it is determined that thevertical distance is greater than or equal to the first preset distanceand is less than the second preset distance, the distance-based UWBoperation method includes performing ranging in the DS-TWR scheme usingthe nearest anchor in S2605 in order to minimize power consumptioninstead of performing ranging in the SS-TWR scheme using N anchors.

When it is determined in S2604 that the vertical distance is greaterthan or equal to the second preset distance, the distance-based UWBoperation method includes performing ranging in the SS-TWR scheme usingthe nearest anchor in S2606.

According to still another embodiment of the present invention, when atag moves away and back again, the original condition is restored.

That is, when the vertical distance is changed from greater than orequal to the second preset distance to greater than or equal to thefirst preset distance and less than the second preset distance, theranging method is also changed such that the ranging is performed in theSS-TWR scheme using N anchors rather than in the SS-TWR scheme using oneanchor.

Also, when the vertical distance is changed from greater than or equalto the first preset distance and less than the second present distanceto less than the first preset distance, the ranging method is alsochanged such that the ranging is performed in the DS-TWR scheme using Nanchors rather than in the DS-TWR scheme using one anchor.

According to another embodiment of the present invention, it is possibleto minimize power consumption in UWB ranging and also to respondappropriately to the situation.

That is, when several anchors continuously range a remote tag, powerconsumption is severe and operation time is long. Thus, by actuatingonly one anchor, it is possible to minimize power consumption, and also,by reducing the number of anchors that perform UWB ranging and bysimplifying the method of performing UWB ranging (from DS-TWR toSS-TWR), it is possible to efficiently perform the UWB rangingoperation.

FIG. 27 shows a UWB ranging sequence that is defined by the CarConnectivity Consortium (CCC) standard on the basis of four anchors.

A frame format used for UWB ranging includes a structure including ascrambled timestamp sequence STS in order to put a timestamp, astructure including a payload without an STS in order to transmit datasuch as a timestamp, etc.

Referring to FIG. 27 , a device 10 transmits a pre-poll to first tofourth anchors 21 to 24 in slot #1. In this case, the device 10 uses aframe format of a structure including a payload without an STS in orderto transmit data such as a timestamp.

The device 10 transmits a poll to the first to fourth anchors 21 to 24in slot #2. In this case, the device 10 uses a frame format of astructure including an STS in order to put a timestamp.

The first to fourth anchors 21 to 24 transmits a response to the device10 in slots #3 to #6, and the device 10 transmits a final message(Final) to the first to fourth anchors 21 to 24 in slot #7.

The device 10 transmits final data to first to fourth anchors 21 to 24in slot #8. In this case, the device 10 uses a frame format of astructure including a payload without the STS in order to transmit dataas with the pre-poll transmission.

According to the related art, digital-key (smartphone) UWB rangingfollows an operation sequence defined by the international standard suchas the CCC.

According to the related art, the corresponding standard associationsuggests that various ranging factors (e.g., STS indices, encryptionkeys, etc.) that need to be selected for UWB communication should beexchanged with smartphones using other communication means (NFC, BLE,etc.) through pre-handshaking.

However, the smart key system according to the related art hasrestrictions on the use of such communication means (NFC, BLE, etc,) andthe pre-exchange of keys.

A UWB system using a UWB ranging factor definition according to stillanother embodiment of the present invention selects a ranging factor andmaintains the same level of security when applying a UWB rangingsequence defined by the international standard (CCC).

According to another embodiment of the present invention, by applyingthe UWB Ranging sequence defined by the international standard (CCC), itis possible to provide a communication scheme optimized by physicalcharacteristics of UWB (e.g., communication interference due toNLOS-obstacle interference).

According to still another embodiment of the present invention, it ispossible to most efficiently derive a ranging factor that needs to bepredefined, and it is also possible to share the ranging factor betweena vehicle and a smart key so that the UWB ranging defined by theinternational standard is available while the current smart key systemis used.

FIG. 28 shows a UWB system using a UWB ranging factor definitionaccording to still another embodiment of the present invention.

The UWB system using the UWB ranging factor definition according tostill another embodiment of the present invention includes a memory 107in which a UWB ranging factor definition program is embedded and aprocessor 108 which executes the program, wherein the processor 108predefines UWB ranging factors to define an STS index, an encryptionkey, and a nonce.

The processor 108 defines an STS index as plaintext that has to beencrypted to generate an STS.

The processor 108 defines STS encryption key, Data encryption key, andSTS Index encryption key as encryption keys.

The processor 108 defines Salt, source (SRC) Address, and RandomCounteras nonces.

The processor 108 defines STS indices, encryption keys, and nonces inconsideration of characteristic information by using encryption keyvalues that are created according to the same rule on the basis ofrandom values provided by a device or seed values provided by a vehicle.

The processor 108 determines the STS indices in consideration of a4-byte random value characteristic that is changed every ranging.

The processor 108 determines the encryption keys in consideration of aunique 16-byte key characteristic for each set of a vehicle and a device(smart key).

The processor 108 determines the nonces in consideration of a unique keycharacteristic (a fixed value different for each smart key) of anindividual device (smart key).

The STS indices are defined as plaintext that has to be encrypted togenerate an STS, STS encryption key, Data encryption key, STS Indexencryption key are defined as encryption keys, and Salt, source (SRC)Address, and RandomCounter are defined as nonces.

The above-described three types of values are encryption key values thatare created by a digital key (smartphone) on the basis of a random valuepre-provided by a smartphone and a seed value provided by a vehicleaccording to the same rule.

The STS index is determined in consideration of a 4-byte random valuecharacteristic that is changed every ranging.

The encryption key is determined in consideration of a unique 16-bytekey (fixed value different for each vehicle) characteristic for each setof a vehicle and a smart key.

Basically, two trained smart keys are provided per vehicle (SMK), and upto four smart keys may be provided. The nonce is determined inconsideration of a unique key (fixed value different for each smart key)characteristic of an individual smart key.

According to still another embodiment of the present invention, it ispossible to allow sharing between a vehicle and a fob so that the smartkey system can perform the most efficient derivation in consideration ofthe above characteristics.

In the case of the STS index, the device creates a 4-byte random valueand forwards the random value through a pre-poll every ranging.

Since the pre-poll has no STS and only data, the STS of the poll,response, and final message is created using the STS index included inthe data.

Since the encryption key is a different value for each vehicle, theencryption key includes PIN, VIN, or ISK (a secret key that is createdusing PIN and VIN and shared in the smart key training operation).

In relation to the nonce, numbers are given to a first anchor, a secondanchor, a third anchor, and a fourth anchor according to the trainingorder of the fob, and these numbers are used as nonces.

Meanwhile, the UWB operation method according to an embodiment of thepresent invention may be implemented in a computer system or recorded ona recording medium. The computer system may include at least oneprocessor, memory, user input device, data communication bus, useroutput device, and storage. The above-described elements perform datacommunication through the data communication bus.

The computer system may further include a network interface coupled to anetwork. The processor may be a central processing unit (CPU) or asemiconductor device for processing instructions stored in a memoryand/or a storage.

The memory and storage may include various types of volatile ornon-volatile storage media. For example, the memory may include aread-only memory (ROM) and a random access memory (RAM).

Accordingly, the UWB operation method according to an embodiment of thepresent invention may be implemented in a computer-executable manner.When the UWB operation method according to an embodiment of the presentinvention is performed by a computer device, computer-readableinstructions may implement the UWB operation method according to anembodiment of the present invention.

Meanwhile, the UWB operation method according to the present inventionmay be embodied as computer-readable code on a computer-readablerecording medium. The computer-readable recording medium includes anytype of recording medium in which data that can be decrypted by acomputer system is stored. For example, the computer-readable recordingmedium may include a ROM, a RAM, a magnetic tape, a magnetic disk, aflash memory, an optical data storage device, and the like. Further, thecomputer-readable recording medium can be stored and carried out ascodes that are distributed in a computer system connected to a computernetwork and that are readable in a distributed manner.

According to an embodiment of the present invention, by applying the UWBRanging sequence defined by the international standard (CCC), it ispossible to provide a communication scheme optimized by physicalcharacteristics of UWB (e.g., communication interference due toNLOS-obstacle interference).

Advantageous effects of the present invention are not limited to theaforementioned effect, and other effects not described herein will beclearly understood by those skilled in the art from the abovedescription.

The present invention has been described above with respect toembodiments thereof. Those skilled in the art should understand thatvarious changes in form and details may be made herein without departingfrom the essential characteristics of the present invention. Therefore,the embodiments described herein should be considered from anillustrative aspect rather than from a restrictive aspect. The scope ofthe present invention should be defined not by the detailed descriptionbut by the appended claims, and all differences falling within a scopeequivalent to the claims should be construed as being encompassed by thepresent invention.

The components described in the example embodiments may be implementedby hardware components including, for example, at least one digitalsignal processor (DSP), a processor, a controller, anapplication-specific integrated circuit (ASIC), a programmable logicelement, such as an FPGA, other electronic devices, or combinationsthereof. At least some of the functions or the processes described inthe example embodiments may be implemented by software, and the softwaremay be recorded on a recording medium. The components, the functions,and the processes described in the example embodiments may beimplemented by a combination of hardware and software.

The method according to example embodiments may be embodied as a programthat is executable by a computer, and may be implemented as variousrecording media such as a magnetic storage medium, an optical readingmedium, and a digital storage medium.

Various techniques described herein may be implemented as digitalelectronic circuitry, or as computer hardware, firmware, software, orcombinations thereof. The techniques may be implemented as a computerprogram product, i.e., a computer program tangibly embodied in aninformation carrier, e.g., in a machine-readable storage device (forexample, a computer-readable medium) or in a propagated signal forprocessing by, or to control an operation of a data processingapparatus, e.g., a programmable processor, a computer, or multiplecomputers. A computer program(s) may be written in any form of aprogramming language, including compiled or interpreted languages andmay be deployed in any form including a stand-alone program or a module,a component, a subroutine, or other units suitable for use in acomputing environment. A computer program may be deployed to be executedon one computer or on multiple computers at one site or distributedacross multiple sites and interconnected by a communication network.

Processors suitable for execution of a computer program include, by wayof example, both general and special purpose microprocessors, and anyone or more processors of any kind of digital computer. Generally, aprocessor will receive instructions and data from a read-only memory ora random access memory or both. Elements of a computer may include atleast one processor to execute instructions and one or more memorydevices to store instructions and data. Generally, a computer will alsoinclude or be coupled to receive data from, transfer data to, or performboth on one or more mass storage devices to store data, e.g., magnetic,magneto-optical disks, or optical disks. Examples of informationcarriers suitable for embodying computer program instructions and datainclude semiconductor memory devices, for example, magnetic media suchas a hard disk, a floppy disk, and a magnetic tape, optical media suchas a compact disk read only memory (CD-ROM), a digital video disk (DVD),etc. and magneto-optical media such as a floptical disk, and a read onlymemory (ROM), a random access memory (RAM), a flash memory, an erasableprogrammable ROM (EPROM), and an electrically erasable programmable ROM(EEPROM) and any other known computer readable medium. A processor and amemory may be supplemented by, or integrated into, a special purposelogic circuit.

The processor may run an operating system (OS) and one or more softwareapplications that run on the OS. The processor device also may access,store, manipulate, process, and create data in response to execution ofthe software. For purpose of simplicity, the description of a processordevice is used as singular; however, one skilled in the art will beappreciated that a processor device may include multiple processingelements and/or multiple types of processing elements. For example, aprocessor device may include multiple processors or a processor and acontroller. In addition, different processing configurations arepossible, such as parallel processors.

Also, non-transitory computer-readable media may be any available mediathat may be accessed by a computer, and may include both computerstorage media and transmission media.

The present specification includes details of a number of specificimplements, but it should be understood that the details do not limitany invention or what is claimable in the specification but ratherdescribe features of the specific example embodiment. Features describedin the specification in the context of individual example embodimentsmay be implemented as a combination in a single example embodiment. Incontrast, various features described in the specification in the contextof a single example embodiment may be implemented in multiple exampleembodiments individually or in an appropriate sub-combination.Furthermore, the features may operate in a specific combination and maybe initially described as claimed in the combination, but one or morefeatures may be excluded from the claimed combination in some cases, andthe claimed combination may be changed into a sub-combination or amodification of a sub-combination.

Similarly, even though operations are described in a specific order onthe drawings, it should not be understood as the operations needing tobe performed in the specific order or in sequence to obtain desiredresults or as all the operations needing to be performed. In a specificcase, multitasking and parallel processing may be advantageous. Inaddition, it should not be understood as requiring a separation ofvarious apparatus components in the above described example embodimentsin all example embodiments, and it should be understood that theabove-described program components and apparatuses may be incorporatedinto a single software product or may be packaged in multiple softwareproducts.

It should be understood that the example embodiments disclosed hereinare merely illustrative and are not intended to limit the scope of theinvention. It will be apparent to one of ordinary skill in the art thatvarious modifications of the example embodiments may be made withoutdeparting from the spirit and scope of the claims and their equivalents.

What is claimed is:
 1. An ultra-wideband (UWB) system comprising: amemory in which a UWB ranging factor definition program is embedded; anda processor which executes the program, wherein the processor predefinesUWB ranging factors to define a scrambled timestamp sequence (STS)index, an encryption key, and a nonce; wherein the processor defines STSencryption key, Data encryption key, and STS Index encryption key as theencryption keys.
 2. The UWB system of claim 1, wherein the processordefines the STS index as plaintext to be encrypted to generate an STS.3. The UWB system of claim 1, wherein the processor defines Salt, source(SRC) Address, and RandomCounter as the nonces.
 4. The UWB system ofclaim 1, wherein the processor defines the STS index, the encryptionkey, and the nonce in consideration of characteristic information byusing encryption key values created according to the same rule on thebasis of a random value provided by a device or a seed value provided bya vehicle.
 5. The UWB system of claim 4, wherein the processordetermines the STS index in consideration of a characteristic of ann-byte random value that is changed every ranging.
 6. The UWB system ofclaim 5, wherein the n-byte random value is delivered through a pre-pollevery ranging, and STS of a poll, a response, and a final message arecreated using the determined STS index.
 7. The UWB system of claim 4,wherein the processor determines the encryption key in consideration ofa unique m-byte key characteristic for each set of a vehicle and adevice.
 8. The UWB system of claim 4, wherein the processor determinesthe nonce in consideration of a unique key characteristic of anindividual device.
 9. The UWB system of claim 8, wherein numbersassigned according to a training order of the individual devices areused as the nonces.
 10. An ultra-wideband (UWB) system comprising: amemory in which a UWB ranging factor definition program is embedded; anda processor which executes the program, wherein the processor predefinesUWB ranging factors to define a scrambled timestamp sequence (STS)index, an encryption key, and a nonce; wherein the processor definesSalt, source (SRC) Address, and RandomCounter as the nonces.
 11. Anultra-wideband (UWB) system comprising: a memory in which a UWB rangingfactor definition program is embedded; and a processor which executesthe program, wherein the processor predefines UWB ranging factors todefine a scrambled timestamp sequence (STS) index, an encryption key,and a nonce; wherein the processor defines the STS index, the encryptionkey, and the nonce in consideration of characteristic information byusing encryption key values created according to the same rule on thebasis of a random value provided by a device or a seed value provided bya vehicle.